The present invention relates to 4-chloromethylphenyl methyl dichlorosilane, which is a novel organosilicon compound not known in the prior art or not described in any printed publications.
As is well known, the starting materials of silicone resins or, generally, silicone products are various kinds of organochlorosilanes. Methyl chlorosilanes and phenylchlorosilanes as the typical classes of the organochlorosilanes are produced by the so-called "direct method", in which metallic silicon in a powdery form is reacted with methyll chloride or chlorobenzene in the presence of powdery copper as the catalyst to give a mixture of methyl chlorosilanes or mixture of phenyl chlorosilanes. When a different kind of the hydrocarbon group bonded to the silicon atom of the silane is desired by introducing into an organochlorosilane as in the preparation of methyl phenyl dichlorosilane from methyl trichlorosilane, a Grignard process is applicable. Namely, for example, methyl trichlorosilane is reacted with phenyl magnesium chloride, i.e. the Grignard reagent of chlorobenzene to replace one of the chlorine atoms in the methyl trichlorosilane with a phenyl group. A great variety of organochlorosilanes are being industrially produced by the combinations of the "direct method" and the Grignard reaction and are used as the starting materials for the preparation of silicone products.
Namely, the silicone products or, in particular, silicone resins are produced by the (co)hydrolysis of an organochlorosilane or a mixture of two kinds or more of organochlorosilanes followed by the polycondensation between the silanol groups formed by the hydrolysis of the silicon-bonded chlorine atoms. Accordingly, the most fundamental key factor influencing the properties of the silicone product is the kinds and combination of the starting organochlorosilanes and the intensively continued investigations conducted in this connection in the technology of silicones for many years have exhaustively developed the possibility of obtaining a new silicone product to meet the requirements for a material useful in modern high-technologies.
For example, the application fields of silicone resins are rapidly expanding in the electronics and other high-technologies with requirements for the silicone products to have higher and higher improved properties. Notwithstanding the requirements in the application fields, it is a general impression in the silicone technology that great improvements in the properties of new silicone products over the existing ones can hardly be expected or a limitation is being approached insofar as the organochlorosilanes as the starting materials of the silicone products are selected among known ones having relatively simple molecular structures. Taking a silicone-based photoresist resin used in the processing of semiconductor devices as an example, it is eagerly desired to develop a silicone resin having a structure susceptible to photo-induced decomposition or crosslinking in a molecule and still having high resistance against heat and the conditions of etching. The inventors also continued investigations on this problem only to be led to a conclusion that no combination of conventional methyl chlorosilanes and phenylchlorosilanes as well as other known organochlorosilanes could provide a possibility of obtaining a novel silicone resin product to meet the requirements in the modern applicaiton fields. Therefore, it is one of the important ways of investigations in the technology of silicones to discover a novel organochlorosilane compound useful as a starting material of high-performance silicone resins.